pl/sql programming help

Im very new to the world of pl/sql and i'm sorta stuck on the following
problem. I partially have part of the code to implement my solution but I
am having problems understanding implicit cursors. Any help would be
greatly appreciated. Thanks in advance.

Here's the problem: Modify the code and make use of cursor attributes to
test whether cursor is open or closed, whether update is successful, if yes,
commit the update and output how many records updated, if not, output an
message saying update is not successful. Hints:
a.. Modify where clause, using deptno 20 (with records) and 40 (without
record) when you test your code.
b.. Use DBMS_OUPUT built-in to output your results.
c.. SQL can be used as Implicit cursor name in front of cursor attributes,
like SQL%FOUND.
Here's the code I have so far:
declare